Blueprint Medicines initiates Phase III trial of avapritinib to treat patients with advanced GIST.

Blueprint Medicines has dosed the first patient in the VOYAGER Phase III clinical trial, which is evaluating the safety and efficacy of avapritinib (BLU 285) compared to regorafenib in patients with advanced gastrointestinal stromal tumors (GIST). The VOYAGER trial is designed to enroll patients previously treated with imatinib and one or two additional tyrosine kinase inhibitors (TKIs).

The VOYAGER clinical trial is a global, open-label, randomized, Phase III trial designed to evaluate the safety and efficacy of avapritinib versus regorafenib in patients with third- or fourth-line advanced GIST. Eligible patients will have previously received imatinib and one or two additional tyrosine kinase inhibitors. The trial is designed to enroll approximately 460 patients randomized 1:1 to receive avapritinib dosed at 300 mg once daily (QD) or regorafenib dosed at 160 mg QD for three weeks, followed by one week off, at multiple sites in the United States, European Union, Australia and Asia. Patients who are randomized to receive regorafenib and experience disease progression confirmed by central radiology review may be offered the opportunity to cross-over to the avapritinib treatment arm.

The primary efficacy endpoint is progression free survival determined by central radiologic assessment per modified Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Secondary endpoints include objective response rate, overall survival and quality of life outcome measures. Regorafenib, also known as Stivarga, is an oral, multi-kinase inhibitor approved by the FDA for the treatment of patients with third-line GIST.